Prompt to delete the installation folder if it already exists

build-telemac.bat

@@ -130,10 +130,25 @@ if %errorlevel% == 1 (
 )
 
 rem *************
-rem Clone Telemac 
+rem Clone Telemac
 rem *************
-rd /s/q %install_path% 2>nul
-git clone -b %version% https://gitlab.pam-retd.fr/otm/telemac-mascaret.git %install_path% || exit /b 0
+set clone=n
+if exist %install_path% (
+  set /p clone=""%install_path%" already exists, do yo want to remove it (y[n])? "
+) else (
+  set clone=y
+)
+if /i "%clone%" equ "y" (
+    rd /s/q %install_path% 2>nul
+    git clone -b %version% https://gitlab.pam-retd.fr/otm/telemac-mascaret.git %install_path% || exit /b 0
+) else (
+    pushd %install_path%
+    echo Switching to %version% branch...
+    git switch %version% || exit /b 0
+    echo Updating %version% branch... 
+    git pull --rebase || exit /b 0
+    popd
+)
 
 rem **********************
 rem Build the dependencies